Adapting the mixture comprising fuel and combustion air is dependent to a particular extent on the atmospheric pressure and, more specifically, on the altitude of the site of use of the work apparatus. It is known that the user can use a corresponding work tool to make adjustments to the mixture formation unit of the combustion engine for the purpose of adapting the elevation of the site of work, for example by manually turning the carburetor screw using a work tool such as a screwdriver or the like. This is complicated and requires a work tool to be carried. The mixture comprising fuel and combustion air is expediently also adapted when components of the work apparatus have been cleaned or replaced, such as an air filter which purifies the combustion air for example.